This invention relates generally to 5,5-disubstituted-1,5-dihydro-4,1-benzoxazepin-2(3H)-ones which are useful as inhibitors of HIV reverse transcriptase, pharmaceutical compositions and diagnostic kits comprising the same, and methods of using the same for treating viral infection or as assay standards or reagents.
Two distinct retroviruses, human immunodeficiency virus (HIV) type-1 (HIV-1) or type-2 (HIV-2), have been etiologically linked to the immunosuppressive disease, acquired immunodeficiency syndrome (AIDS). HIV seropositive individuals are initially asymptomatic but typically develop AIDS related complex (ARC) followed by AIDS. Affected individuals exhibit severe immunosuppression which predisposes them to debilitating and ultimately fatal opportunistic infections.
The disease AIDS is the end result of an HIV-1 or HIV-2 virus following its own complex life cycle. The virion life cycle begins with the virion attaching itself to the host human T-4 lymphocyte immune cell through the bonding of a glycoprotein on the surface of the virion""s protective coat with the CD4 glycoprotein on the lymphocyte cell. Once attached, the virion sheds its glycoprotein coat, penetrates into the membrane of the host cell, and uncoats its RNA. The virion enzyme, reverse transcriptase, directs the process of transcribing the RNA into single-stranded DNA. The viral RNA is degraded and a second DNA strand is created. The now double-stranded DNA is integrated into the human cell""s genes and those genes are used for virus reproduction.
At this point, RNA polymerase transcribes the integrated DNA into viral RNA. The viral RNA is translated into the precursor gag-pol fusion polyprotein. The polyprotein is then cleaved by the HIV protease enzyme to yield the mature viral proteins. Thus, HIV protease is responsible for regulating a cascade of cleavage events that lead to the virus particle""s maturing into a virus that is capable of full infectivity.
The typical human immune system response, killing the invading virion, is taxed because the virus infects and kills the immune system""s T cells. In addition, viral reverse transcriptase, the enzyme used in making a new virion particle, is not very specific, and causes transcription mistakes that result in continually changed glycoproteins on the surface of the viral protective coat. This lack of specificity decreases the immune system""s effectiveness because antibodies specifically produced against one glycoprotein may be useless against another, hence reducing the number of antibodies available to fight the virus. The virus continues to reproduce while the immune response system continues to weaken. Eventually, the HIV largely holds free reign over the body""s immune system, allowing opportunistic infections to set in and without the administration of antiviral agents, immunomodulators, or both, death may result.
There are at least three critical points in the virus""s life cycle which have been identified as possible targets for antiviral drugs: (1) the initial attachment of the virion to the T-4 lymphocyte or macrophage site, (2) the transcription of viral RNA to viral DNA (reverse transcriptase, RT), and (3) the processing of gag-pol protein by HIV protease.
Inhibition of the virus at the second critical point, the viral RNA to viral DNA transcription process, has provided a number of the current therapies used in treading AIDS. This transcription must occur for the virion to reproduce because the virion""s genes are encoded in RNA and the host cell reads only DNA. By introducing drugs that block the reverse transcriptase from completing the formation of viral DNA, HIV-1 replication can be stopped.
A number of compounds that interfere with viral replication have been developed to treat AIDS. For example, nucleoside analogs, such as 3xe2x80x2-azido-3xe2x80x2-deoxythymidine (AZT), 2xe2x80x2,3xe2x80x2-dideoxycytidine (ddC), 2xe2x80x2,3xe2x80x2-dideoxythymidinene (d4T), 2xe2x80x2,3xe2x80x2-dideoxyinosine (ddI), and 2xe2x80x2,3xe2x80x2-dideoxy-3xe2x80x2-thia-cytidine (3TC) have been shown to be relatively effective in halting HIV replication at the reverse transcriptase (RT) stage.
Non-nucleoside HIV reverse transcriptase inhibitors have also been discovered. As an example, it has been found that certain benzoxazinones are useful in the inhibition of HIV reverse transcriptase, the prevention or treatment of infection by HIV and the treatment of AIDS. U.S. Pat. No. 5,519,021, the contents of which are hereby incorporated herein by reference, describes reverse transcriptase inhibitors which are benzoxazinones of the formula: 
wherein X is a halogen, Z may be O. However, benzoxazinones are not part of the present invention.
U.S. Pat. No. 4,476,133 depicts CNS active 4,1-benzoxazepines of the formula: 
wherein A-B can be NHxe2x80x94C(O), R is H or C1-5 alkyl, X is H, halo, or NO2, and Y is phenyl or pyridyl. No mention is made of 5,5-disubstituted-1,5-dihydro-4,1-benzoxazepin-2(3H)-ones which are the subject of the present invention.
EP 0,142,361 illustrates phospholipase A2 inhibitors of the formula: 
wherein R1 can be a variety of cyclic and acyclic groups, but not hydrogen, R2 is H, alkyl, or phenyl, and Y1 is H, halo, NO2 or CF3. Compounds of the present invention have a hydrogen at the 1-position and do not have a phenyl group directly attached to the 5-position.
EP 0,567,026 and JP 08/259,447, which have similar disclosures, describe 4,1-benzoxazepinone derivatives of the formula: 
wherein ring A may be optionally substituted phenyl (also optionally substituted heteroaryl in JP ""447), R1, R2, and R3 can be a variety of groups including H and optionally substituted hydrocarbon, X is a bond or spacer and Y (B in JP ""447) is optionally substituted carboxyl, hydroxyl, amino, phenyl, carbamoyl, or a nitrogen-containing heterocycle. In JP ""447, B is only optionally substituted phenyl or nitrogen-containing heterocycle. Compounds of this sort are not within the presently claimed invention.
Even with the current success of reverse transcriptase inhibitors, it has been found that HIV patients can become resistant to a single inhibitor. Thus, it is desirable to develop additional inhibitors to further combat HIV infection.
Accordingly, one object of the present invention is to provide novel reverse transcriptase inhibitors.
It is another object of the present invention to provide a novel method for treating HIV infection which comprises administering to a host in need of such treatment a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt or prodrug form thereof.
It is another object of the present invention to provide a novel method for treating HIV infection which comprises administering to a host in need thereof a therapeutically effective combination of (a) one of the compounds of the present invention and (b) one or more compounds selected form the group consisting of HIV reverse transcriptase inhibitors and HIV protease inhibitors.
It is another object of the present invention to provide pharmaceutical compositions with reverse transcriptase inhibiting activity comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of at least one of the compounds of the present invention or a pharmaceutically acceptable salt or prodrug form thereof.
It is another object of the present invention to provide a method of inhibiting HIV present in a body fluid sample which comprises treating the body fluid sample with an effective amount of a compound of the present invention.
It is another object of the present invention to provide a kit or container containing at least one of the compounds of the present invention in an amount effective for use as a standard or reagent in a test or assay for determining the ability of a potential pharmaceutical to inhibit HIV reverse transcriptase, HIV growth, or both.
These and other objects, which will become apparent during the following detailed description, have been achieved by the inventors"" discovery that compounds of formula (I): 
wherein A, W, X, Y, Z, Ra, Rb, R1 and R2 are defined below, stereoisomeric forms, mixtures of stereoisomeric forms, or pharmaceutically acceptable salt forms thereof, are effective reverse transcriptase inhibitors.
[1] Thus, in a first embodiment, the present invention provides a novel compound of formula I: 
xe2x80x83or a stereoisomer or pharmaceutically acceptable salt form thereof, wherein:
A is O or S;
W is N or CR3;
X is N or CR4;
Y is N or CR5;
Z is N or CR6;
provided that if two of W, X, Y, and Z are N, then the remaining are other than N;
Ra is selected from H, CF3, CF2H, cycPr, C1-4 alkyl, C3-5 cycloalkyl, C2-4 alkenyl, C2-4 alkynyl, and phenyl substituted with 0-2 R10;
Rb is selected from H, CF3, CF2H, cycPr, C1-4 alkyl, C3-5 cycloalkyl, C2-4 alkenyl, C2-4 alkynyl, and phenyl substituted with 0-2 R10;
alternatively, Ra and Rb together form xe2x80x94(CH2)nxe2x80x94;
R1 is selected from CF3, CF2H, C1-4 alkyl, C3-5 cycloalkyl, C2-4 alkenyl, and C2-4 alkynyl;
R2 is selected from xe2x80x94Cxe2x89xa1Cxe2x80x94R8, xe2x80x94CHxe2x95x90CR7R8, xe2x80x94(CH2)pCHR7R8, xe2x80x94CHR7Cxe2x89xa1Cxe2x80x94R8, xe2x80x94CHR7CHxe2x95x90CHR8, and CHxe2x95x90CHCHR7R8;
provided that when either of Ra or Rb is phenyl, then R1 is other than C1-4 alkyl and C3-5 cycloalkyl and R2 is other than xe2x80x94(CH2)pCHR7R8;
R3 is selected from H, F, Cl, Br, I, C1-3 alkoxy, and C1-3 alkyl;
R4 is selected from H, F, Cl, Br, I, C1-3 alkyl substituted with 0-3 R11, C2-3 alkenyl, C2-3 alkynyl, C1-3 alkoxy, OCF3, xe2x80x94CN, NO2, CHO, C(O)CH3, C(O)CF3, C(O)NH2, C(O)NHCH3, NR7R7a, NR7C(O)OR7b, C(O)OR7, S(O)pR7, SO2NHR7, NR7SO2R7b, phenyl substituted with 0-2 R10, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S and substituted with 0-2 R10;
alternatively, R3 and R4 together form xe2x80x94OCH2Oxe2x80x94;
R5 is selected from H, F, Cl, Br, and I;
alternatively, R4 and R5 together form xe2x80x94OCH2Oxe2x80x94 or a fused benzo ring;
R6 is selected from H, OH, C1-3 alkoxy, xe2x80x94CN, F, Cl, Br, I, NO2, CF3, CHO, C1-3 alkyl, and C(O)NH2;
R7, at each occurrence, is selected from H and C1-3 alkyl;
R7a, at each occurrence, is selected from H and C1-3 alkyl;
R7b, at each occurrence, is C1-3 alkyl;
R8, at each occurrence, is selected from H, C1-6 alkyl substituted with 0-3 R11, CH(xe2x80x94OCH2CH2Oxe2x80x94), C2-6 alkenyl, C3-7 cycloalkyl substituted with 0-2 R9, phenyl substituted with 0-2 R10, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S and substituted with 0-2 R10;
R9, at each occurrence, is selected from D, OH, C1-3 alkoxy, C1-3 alkyl, and F;
R10, at each occurrence, is selected from OH, C1-3 alkyl, C1-3 alkoxy, F, Cl, Br, I, CN, NR7R7a, and C(O)CH3;
R11, at each occurrence, is selected from OR7, CN, F, Cl, Br, I, NO2, NR7R7a, CHO, C(O)CH3, C(O)NH2;
n, at each occurrence, is selected from 1, 2, 3, 4, and 5; and,
p, at each occurrence, is selected from 0, 1, and 2.
[2] In a preferred embodiment, the present invention provides a novel compound of formula I, wherein:
Ra is H;
Rb is selected from H, CF3, CF2H, cyclopropyl, CHxe2x95x90CH2, and C1-4 alkyl;
R1 is selected from CF3, CF2H, C1-3 alkyl, and C3-5 cycloalkyl; and,
R8 is selected from H, C1-6 alkyl substituted with 0-3 R11, CH(xe2x80x94OCH2CH2Oxe2x80x94), C2-6 alkenyl, C3-5 cycloalkyl substituted with 0-1 R9, phenyl substituted with 0-1 R10, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-1 R10.
[3] In a more preferred embodiment, the present invention provides a novel compound of formula I, wherein:
A is O;
R1 is selected from CF3, CF2H, C2H5, isopropyl, and cyclopropyl;
R3 is selected from H, F, Cl, Br, I, OCH3, and CH3;
R4 is selected from H, F, Cl, Br, I, C1-3 alkyl substituted with 0-3 R11, C2-3 alkenyl, C2-3 alkynyl, C1-3 alkoxy, OCF3, xe2x80x94CN, NO2, CHO, C(O)CH3, C(O)CF3, C(O)NH2, C(O)NHCH3, NR7R7a, NR7C(O)OR7b, C(O)OR7, S(O)pR7, SO2NHR7, NR7SO2R7b, phenyl, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S;
alternatively, R3 and R4 together form xe2x80x94OCH2Oxe2x80x94;
R5 is selected from H and F;
R6 is selected from H, OH, OCH3, xe2x80x94CN, F, CF3, CH3, and C(O)NH2;
R7 is selected from H and CH3;
R7a is selected from H and CH3;
R7b is CH3;
R8 is selected from H, C1-4 alkyl substituted with 0-3 R11, CH(xe2x80x94OCH2CH2Oxe2x80x94), C2-4 alkenyl, C3-5 cycloalkyl substituted with 0-1 R9, phenyl substituted with 0-1 R10, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S substituted with 0-1 R10;
R9 is selected from D, OH, OCH3, CH3, and F;
R10 is selected from OH, CH3, OCH3, F, Cl, Br, I, CN, NR7R7a, and C(O)CH3; and,
p is selected from 1 and 2.
[4] In an even more preferred embodiment, the present invention provides a novel compound of formula I, wherein:
Rb is selected from H, CF3, CF2H, cyclopropyl, CHxe2x95x90CH2, CH3, and CH2CH3;
R1 is selected from CF3, CF2H, and cyclopropyl;
R2 is selected from xe2x80x94Cxe2x89xa1Cxe2x80x94R8 and trans-CHxe2x95x90CR7R8;
R3 is selected from H, F, Cl, Br, and I;
R4 is selected from H, F, Cl, Br, I, C1-3 alkyl substituted with 0-3 R11, CHxe2x95x90CH2, Cxe2x89xa1CH, OCH3, OCF3, xe2x80x94CN, NO2, CHO, C(O)CH3, C(O)CF3, C(O)NH2, C(O)NHCH3, NR7R7a, C(O)OR7, NR7SO2R7b, and 5-6 membered aromatic heterocycle system containing from 1-4 heteroatoms selected from the group consisting of N, O, and S;
alternatively, R3 and R4 together form xe2x80x94OCH2Oxe2x80x94; and,
R11 is selected from OH, OCH3, CN, F, Cl, NR7R7a, C(O)CH3, and C(O)NH2.
[5] In a further preferred embodiment, the compound of the present invention is selected from:
5-(1-Butynyl)-7-chloro-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-5-(1-Butynyl)-7-chloro-1,5-dihydro-3-phenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Chloro-1,5-dihydro-5-(isopropylethynyl)-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
(+)-(5S)-7-Chloro-1,5-dihydro-5-(isopropylethynyl)-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
1,5-Dihydro-7-fluoro-5-isopropylethynyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
1,5-Dihydro-7-fluoro-5-(3-methylbutyl)-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-1,5-dihydro-5-(2-furan-2-ylethenyl)-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-7-Chloro-1,5-dihydro-5-(2-furan-2-yl)ethenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-1,5-dihydro-5-(2-furanyl)ethynyl-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
5-Butyl-7-chloro-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
4-Isopropylethynyl-4-trifluoromethyl-5,6-difluoro-1,4-dihydro-2H-3,1-benzoxazin-2-one.;
rel-(3S,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-propyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3R,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-propyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-isopropyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Chloro-5-phenylethynyl-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-isopropylethynyl-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Chloro-5-cyclopropylethynyl-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Chloro-5-isopropylethynyl-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-7-Chloro-5-(2-isopropylethenyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Methoxy-5-(3-methylbutyl)-1,5-dihydro-S-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3R,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
7-Chloro-5-(3-pyridylethynyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-7-Chloro-5-(3-pyrid-3-ylethenyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-7-Fluoro-5-(2-isopropylethenyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
trans-6,7-Difluoro-5-(2-isopropylethenyl)-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-propyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-(3-furanylethynyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-(3-furanylethynyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Difluoro-5-cyclopropylethynyl-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Difluoro-5-cyclopropylethynyl-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-6,7-Difluoro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
(+)-(3S,5S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
(3S)-7-Chloro-5-cyclopropylethynyl-1,5-dihydro-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
(+)-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
(+)-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-ethenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-ethenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Chloro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-cyclopropyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Chloro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-cyclopropyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Difluoro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-ethenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Difluoro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-cyclopropyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Fluoro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-ethenyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Fluoro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-7-Fluoro-5-(2-cyclopropylethynyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Fluoro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-7-Fluoro-5-(2-cyclopropylethenyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Methylenedioxy-5-(2-cyclopropylethynyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-6,7-Methylenedioxy-5-(2-cyclopropylethynyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
rel-(3S,5S)-trans-6,7-Methylenedioxy-5-(2-cyclopropylethenyl)-1,5-dihydro-3-methyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one; and,
rel-(3S,5S)-trans-6,7-Methylenedioxy-5-(2-cyclopropylethenyl)-1,5-dihydro-3-ethyl-5-(trifluoromethyl)-4,1-benzoxazepin-2(3H)-one;
xe2x80x83or a pharmaceutically acceptable salt form thereof.
[6] In another preferred embodiment, the present invention provides a compound of formula II: 
xe2x80x83or a stereoisomer or pharmaceutically acceptable salt form thereof.
[7] In another more preferred embodiment, the present invention provides a compound of formula IIa: 
xe2x80x83or a stereoisomer or pharmaceutically acceptable salt form thereof, wherein R1 is CF3.
In a second embodiment, the present invention provides a novel pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of a compound of formula I or pharmaceutically acceptable salt form thereof.
In a third embodiment, the present invention provides a novel method for treating HIV infection which comprises administering to a host in need of such treatment a therapeutically effective amount of a compound of formula I or pharmaceutically acceptable salt form thereof.
In a fourth embodiment, the present invention provides a novel method of treating HIV infection which comprises administering, in combination, to a host in need thereof a therapeutically effective amount of:
(a) a compound of formula I; and,
(b) at least one compound selected from the group consisting of HIV reverse transcriptase inhibitors and HIV protease inhibitors.
In another preferred embodiment, the reverse transcriptase inhibitor is a nucleoside reverse transcriptase inhibitor.
In another more preferred embodiment, the nucleoside reverse transcriptase inhibitor is selected from AZT, 3TC, rescriptor, ddI, ddC, efavirenz, and d4T and the protease inhibitor is selected from saquinavir, ritonavir, indinavir, VX-478, nelfinavir, KNI-272, CGP-61755, and U-103017.
In an even more preferred embodiment, the nucleoside reverse transcriptase inhibitor is selected from AZT, efavirenz, rescriptor, and 3TC and the protease inhibitor is selected from saquinavir, ritonavir, indinavir, and nelfinavir.
In a still further preferred embodiment, the nucleoside reverse transcriptase inhibitor is AZT.
In another still further preferred embodiment, the protease inhibitor is indinavir.
In a fifth embodiment, the present invention provides a pharmaceutical kit useful for the treatment of HIV infection, which comprises a therapeutically effective amount of:
(a) a compound of formula I; and,
(b) at least one compound selected from the group consisting of HIV reverse transcriptase inhibitors and HIV protease inhibitors, in one or more sterile containers.
In a sixth embodiment, the present invention provides a novel method of inhibiting HIV present in a body fluid sample which comprises treating the body fluid sample with an effective amount of a compound of formula I.
In a seventh embodiment, the present invention to provides a novel a kit or container comprising a compound of formula (I) in an amount effective for use as a standard or reagent in a test or assay for determining the ability of a potential pharmaceutical to inhibit HIV reverse transcriptase, HIV growth, or both.
As used herein, the following terms and expressions have the indicated meanings. It will be appreciated that the compounds of the present invention contain an asymmetrically substituted carbon atom, and may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis, from optically active starting materials. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomer form is specifically indicated.
The processes of the present invention are contemplated to be practiced on at least a multigram scale, kilogram scale, multikilogram scale, or industrial scale. Multigram scale, as used herein, is preferably the scale wherein at least one starting material is present in 10 grams or more, more preferably at least 50 grams or more, even more preferably at least 100 grams or more. Multikilogram scale, as used herein, is intended to mean the scale wherein more than one kilogram of at least one starting material is used. Industrial scale as used herein is intended to mean a scale which is other than a laboratory scale and which is sufficient to supply product sufficient for either clinical tests or distribution to consumers.
The term xe2x80x9csubstituted,xe2x80x9d as used herein, means that any one or more hydrogens on the designated atom is replaced with a selection from the indicated group, provided that the designated atom""s normal valency is not exceeded, and that the substitution results in a stable compound. When a substitent is keto (i.e., xe2x95x90O), then 2 hydrogens on the atom are replaced. Keto substituents are not present on aromatic moieties.
The present invention is intended to include all isotopes of atoms occurring in the present compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation, isotopes of hydrogen include tritium and deuterium. Isotopes of carbon include C-13 and C-14.
When any variable (e.g., R6) occurs more than one time in any constituent or formula for a compound, its definition at each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0-2 R6, then said group may optionally be substituted with up to two R6 groups and R6 at each occurrence is selected independently from the definition of R6. Also, combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
When a bond to a substituent is shown to cross a bond connecting two atoms in a ring, then such substituent may be bonded to any atom on the ring. When a substituent is listed without indicating the atom via which such substituent is bonded to the rest of the compound of a given formula, then such substituent may be bonded via any atom in such substituent. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds.
As used herein, xe2x80x9calkylxe2x80x9d is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, and s-pentyl. xe2x80x9cHaloalkylxe2x80x9dis intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms, substituted with 1 or more halogen (for example xe2x80x94CvFw where v=1 to 3 and w=1 to (2v+1)). Examples of haloalkyl include, but are not limited to, trifluoromethyl, trichloromethyl, pentafluoroethyl, and pentachloroethyl. xe2x80x9cAlkoxyxe2x80x9d represents an alkyl group as defined above with the indicated number of carbon atoms attached through an oxygen bridge. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, s-butoxy, t-butoxy, n-pentoxy, and s-pentoxy. xe2x80x9cCycloalkylxe2x80x9d is intended to include saturated ring groups, such as cyclopropyl, cyclobutyl, or cyclopentyl. Alkenylxe2x80x9d is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl and propenyl. xe2x80x9cAlkynylxe2x80x9d is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon-carbon bonds which may occur in any stable point along the chain, such as ethynyl and propynyl.
xe2x80x9cHaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d as used herein refers to fluoro, chloro, bromo, and iodo; and xe2x80x9ccounterionxe2x80x9d is used to represent a small, negatively charged species such as chloride, bromide, hydroxide, acetate, and sulfate.
As used herein, xe2x80x9carylxe2x80x9d or xe2x80x9caromatic residuexe2x80x9d is intended to mean an aromatic moiety containing the specified number of carbon atoms, such as phenyl or naphthyl. As used herein, xe2x80x9ccarbocyclexe2x80x9d or xe2x80x9ccarbocyclic residuexe2x80x9d is intended to mean any stable 3- to 7-membered monocyclic or bicyclic which may be saturated, partially unsaturated, or aromatic. Examples of such carbocyles include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, biphenyl, naphthyl, indanyl, adamantyl, or tetrahydronaphthyl (tetralin).
As used herein, the term xe2x80x9cheterocyclexe2x80x9d or xe2x80x9cheterocyclic systemxe2x80x9d is intended to mean a stable 5- to 6-membered monocyclic heterocyclic ring which is saturated partially unsaturated or unsaturated (aromatic), and which consists of carbon atoms and from 1 to 3 heteroatoms independently selected from the group consisting of N, O and S. The nitrogen and sulfur heteroatoms may optionally be oxidized. The heterocyclic ring may be attached to its pendant group at any heteroatom or carbon atom which results in a stable structure. The heterocyclic rings described herein may be substituted on carbon or on a nitrogen atom if the resulting compound is stable. If specifically noted, a nitrogen in the heterocycle may optionally be guaternized. It is preferred that when the total number of S and O atoms in the heterocycle exceeds 1, then these heteroatoms are not adjacent to one another. It is preferred that the total number of S and O atoms in the heterocycle is not more than 1. As used herein, the term xe2x80x9caromatic heterocyclic systemxe2x80x9d is intended to mean a stable 5- to 6-membered monocyclic heterocyclic aromatic ring which consists of carbon atoms and from 1 to 3 heterotams independently selected from the group consisting of N, O and S. It is preferred that the total number of S and O atoms in the aromatic heterocycle is not more than 1.
Examples of heterocycles include, but are not limited to, 2-pyrrolidonyl, 2H-pyrrolyl, 4-piperidonyl, 6H-1,2,5-thiadiazinyl, 2H,6H-1,5,2-dithiazinyl, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, isoxazolyl, morpholinyl, oxadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl, oxazolyl, piperazinyl, piperidinyl, pteridinyl, piperidonyl, 4-piperidonyl, piperonyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, pyrrolyl, tetrahydrofuranyl, 6H-1,2,5-thiadiazinyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl, triazinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, and 1,3,4-triazolyl. Preferred heterocycles include, but are not limited to, pyridinyl, furanyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, and oxazolidinyl. Also included are fused ring and spiro compounds containing, for example, the above heterocycles.
As used herein, xe2x80x9cHIV reverse transcriptase inhibitorxe2x80x9d is intended to refer to both nucleoside and non-nucleoside inhibitors of HIV reverse transcriptase (RT). Examples of nucleoside RT inhibitors include, but are not limited to, AZT, ddC, ddI, d4T, and 3TC. Examples of non-nucleoside RT inhibitors include, but are not limited to, efavirenz (DuPont), rescriptor (delavirdine, Pharmacia and Upjohn), viviradine (Pharmacia and Upjohn U90152S), TIBO derivatives, BI-RG-587, nevirapine, L-697, 661, LY 73497, and Ro 18,893 (Roche).
As used herein, xe2x80x9cHIV protease inhibitorxe2x80x9d is intended to refer to compounds which inhibit HIV protease. Examples include, but are not limited, saquinavir (Roche, Ro31-8959), ritonavir (Abbott, ABT-538), indinavir (Merck, MK-639), VX-478 (Vertex/Glaxo Wellcome), nelfinavir (Agouron, AG-1343), KNI-272 (Japan Energy), CGP-61755 (Ciba-Geigy), DMP450 (DuPont), DMP850 (DuPont), DMP851 (DuPont) and U-103017 (Pharmacia and Upjohn). Additional examples include the cyclic protease inhibitors disclosed in WO93/07128, WO94/19329, WO94/22840, and PCT Application Number US96/03426 and the protease inhibitors disclosed in WO94/04993,WO95/33464, WO96/28,418, and WO96/28,464.
As used herein, xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d refer to derivatives of the disclosed compounds wherein the parent compound is modified by making acid or base salts thereof. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The pharmaceutically acceptable salts include the conventional non-toxic salts or the quaternary ammonium salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, and the like.
The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington""s Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa, 1985, p. 1418, the disclosure of which is hereby incorporated by reference.
The phrase xe2x80x9cpharmaceutically acceptablexe2x80x9d is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication commensurate with a reasonable benefit/risk ratio.
xe2x80x9cProdrugsxe2x80x9d are intended to include any covalently bonded carriers which release the active parent drug according to formula (I) or other formulas or compounds of the present invention in vivo when such prodrug is administered to a mammalian subject. Prodrugs of a compound of the present invention, for example formula (I), are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound. Prodrugs include compounds of the present invention wherein the hydroxy or amino group is bonded to any group that, when the prodrug is administered to a mammalian subject, cleaves to form a free hydroxyl or free amino, respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of the present invention, and the like.
xe2x80x9cStable compoundxe2x80x9d and xe2x80x9cstable structurexe2x80x9d are meant to indicate a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent. Only stable compounds are contempleted by the present invention.
xe2x80x9cTherapeutically effective amountxe2x80x9d is intended to include an amount of a compound of the present invention or an amount of the combination of compounds claimed effective to inhibit HIV infection or treat the symptoms of HIV infection in a host. The combination of compounds is preferably a synergistic combination. Synergy, as described for example by Chou and Talalay, Adv. Enzyme Regul. 22:27-55 (1984), occurs when the effect (in this case, inhibition of HIV replication) of the compounds when administered in combination is greater than the additive effect of the compounds when administered alone as a single agent. In general, a synergistic effect is most clearly demonstrated at suboptimal concentrations of the compounds. Synergy can be in terms of lower cytotoxicity, increased antiviral effect, or some other beneficial effect of the combination compared with the individual components.
The compounds of the present invention can be prepared in a number of ways well known to one skilled in the art of organic synthesis. The compounds of the present invention can be synthesized using the methods described below, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereon as appreciated by those skilled in the art. Each of the references cited below are hereby incorporated herein by reference. 
Scheme 1 illustrates a method of making the oxazepinones of the present invention starting from an appropriately substituted aminoalcohol. The amine is acylated by an xcex1-halo acid halide (preferably an xcex1-bromoacyl bromide) in the presence of a weak base such as pyridine. After acylation, cyclization is effected by further treatment with base. A tertiary amine base such as diisopropylethylamine, sodium hydride, potassium hydride, lithium hydride, sodium carbonate, potassium carbonate or cesium carbonate, sodium or potassium alkoxides or similar bases may be used with cesium carbonate and sodium hydride being preferred. Any non-protic organic solvent may be used for the cyclization reaction with DMF being preferred. In cases where R1 and R2 are different and Ra and Rb are also different, two diastereomers are formed which may be separated by selective crystallization or chromatography. In the case where R1 and R2 are different and either Ra or Rb is H, cyclization with cesium carbonate in the presence of lithium bromide or lithium iodide will often afford a diastereomeric mixture in which one diastereomer greatly predominates. Thus, in some cases these cyclization conditions are greatly preferred. In cases where both Ra and Rb are H, either sodium hydride or cesium carbonate are preferred bases. When an appropriately strong base is used, both acylation and cyclization reactions illustrated in Scheme 1 may be effected in a single step. 
Scheme 2 illustrates a second method of making the oxazepinones of the present invention starting from an appropriately substituted N-tritylaminoalcohol. The hydroxy group is alkylated with an xcex1-haloester in the presence of base, and then after removal of the trityl protecting group, treatment with base and/or heat effects cyclization to the oxazepinone. In some cases it may be preferable to use an unprotected amino group. Also, other protecting groups known to those of skill in the art can be used in place of the shown trityl group. 
Scheme 3 illustrates a method of making 5,5-disubstituted-benzoxazepin-2-ones starting from an appropriately substituted 2-aminobenzoic acid. In Scheme 3, G can be R3, R4, R5 or R6 or a combination of two or more of these groups. The acid is converted to its N-methoxy-N-methyl amide derivative which can then be displaced to obtain the R1-substituted ketone. Subsequent addition of another metallic species provides the alcohol which is readily cyclized by the 2-step procedure described in Scheme 1.
Scheme 4 describes a means of obtaining 5-trifluoromethyl-benzoxazepin-2-ones starting from an appropriately substituted aniline. After iodination, the trifluoromethyl group can be introduced using a strong base and ethyl trifluoroacetate. The second 5-substituent can then be added through anion attack on the ketone or using other means well known to those of skill in the art. Cyclization can be then be completed as in Scheme 1. 
Because certain benzo-substituents are incompatible with the methods of the previous schemes, it may be necessary to protect these groups before forming the benzoxazepinone. In Scheme 5 there is shown a means of obtaining carbonyl-substituted 5,5-disubstituted-benzoxazepin-2-ones. After iodination of an acetyl-aniline, the acetyl group is protected by means well known to those of skill in the art, such as using 1,3-propanedithiol. The same procedures as in Scheme 4 are used to arrive at the cyclized product. Deprotection of the ketone can then be achieved using HgCl2 and HgO or other means well known to those of skill in the art. 
A method for forming 5,5-disubstituted-benzoxazepin-2-ones, wherein R2 is a vinyl or alkynyl group, is described in Scheme 6. Starting from an appropriately substituted ketone which can be obtained using the procedure of Scheme 3 or 4, an acetylide is added. The product can be deprotected and cyclized in two steps (Scheme 1) to obtain the alkynyl-substituted material. Alternatively, the vinyl compounds can be obtained by reduction of the alkyne with a reducing agent, such as LiAlH4, deprotection by standard means, and 2-step cyclization. 
The acetylide which is required for the reactions illustrated in Scheme 6 may be generated directly from a terminal acetylene by treatment with a strong base such as n-butyllithium. An alternate method for generating an acetylide, illustrated in Scheme 6A, is by converting an aldehyde to a 1,1-dibromoolefin which is then reacted with 2 equivalents of n-butyllithium. 
Scheme 7 describes an alternate route to 5,5-disubstituted-benzoxazepin-2-ones from anilines, wherein the aniline is protected, ester addition is accomplished using a strong base and the amine protecting group is removed. The R2 group can then be added, e.g. via an acetylide, followed by cyclization as in Scheme 1. 
An intermediate useful in the preparation of the presently claimed compounds is 2-trifluoroacetylaniline. The starting 4-chloro-2-trifluoroacetylaniline can be made as shown in Scheme 4. Reduction and reoxidation removes the chloro group leaving the desired intermediate. 
Scheme 9 describes a novel method of making 2-trifluoroacetylanilines as well as how these compounds can be further modified to make the presently claimed compounds. The protected aldehyde can be made from the N-methoxy-N-methyl amide of Scheme 3, by addition of a protecting group, preferably trityl, and reduction of the amide to the aldehyde. Other protecting groups known to those of skill in the art can be used in place of the shown trityl group. 
Scheme 10 illustrates specific steps of Scheme 9. Intermediate IIIb (R1a is selected from CF3, CF3CF2, and CF3CF2CF2) is useful for making some of the presently claimed compounds. Pg is an amine protecting group as defined previously, preferably trityl (triphenylmethyl). The protected or unprotected aminobenzaldehyde, preferably protected, is treated with a perfluoralkyl trimethylsilane, preferably trifluoromethyl trimethylsilane, followed by fluoride anion, preferably tetrabutylammonium fluoride. In the same fashion, CF3CF2TMS, CF3CF2CF2TMS can also be used to prepare the appropriately substituted ketones. Other sources of fluoride anion such as sodium fluoride, potassium fluoride, lithium fluoride, cesium fluoride as well as oxyanionic species such as potassium tert-butoxide, sodium methoxide, sodium ethoxide and sodium trimethylsilanolate can also be used. Aprotic solvents such as DMF and THF can be used, preferably THF. The amount of perfluoralkyl trimethylsilane used can be from about 1 to about 3 equivalents with an equivalent amount of fluoride anion or oxyanionic species. The reaction can be typically carried out at temperatures between about xe2x88x9220xc2x0 C. to about 50xc2x0 C., preferably about xe2x88x9210 to about 10xc2x0 C., more preferably about 0xc2x0 C.
Conversion of IIIb to IIIc can be achieved by using an oxidizing agent well known to one of skill in the art such as MnO2, PDC, PCC, K2Cr2O7, CrO3, KMnO4, BaMnO4, Pb(OAc)4, and RuO4. A preferred oxidant is MnO2. Such conversion can be performed in an aprotic solvent like THF, DMF, dichloromethane, dichloroethane, or tetrachloroethane, preferably dichloromethane. 
An additional means of making 5-alkynyl-benzoxazepin-2-ones is shown in Scheme 11. The alkyne group is added to the keto-aniline via a Grignard type addition, followed by cyclization. The alkyne group of the product can then be modified to obtain the desired compound. 
In addition to the methods of obtaining keto-anilines described in Schemes 3 and 4, nucleophilic opening of isatoic anhydrides can also be used as shown in Scheme 12. This reaction is accomplished by using an anionic nucleophile of the group R1a. See Mack et al, J. Heterocyclic Chem. 1987, 24, 1733-1739; Coppola et al, J. Org. Chem. 1976, 41(6), 825-831; Takimoto et al, Fukuoka Univ. Sci. Reports 1985, 15(1), 37-38; Kadin et al, Synthesis 1977, 500-501; Staiger et al, J. Org. Chem. 1959, 24, 1214-1219.
It is preferred that the stoichiometry of the isatoic anhydride reagent to nucleophile is about 1.0 to 2.1 molar equivalents. The use of 1.0 eq. or more (e.g., 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0) of anion (or anion precursor) is preferred to force the conversion and improve the isolated yield. Preferably, the temperature used is from xe2x88x9220 to +35xc2x0 C., with temperatures below 0xc2x0 C. being more preferred and xe2x88x9220xc2x0 C. being even more preferred. Reactions are run to about completion with time dependent upon inter alia nucleophile, solvent, and temperature. Preferably this nucleophilic addition is run in THF, but any aprotic solvent would be suitable. Reaction with the active nucleophilic anion is the only criterion for exclusion of a solvent. 
Scheme 13 illustrates the synthesis of a 3,3-disubstituted oxazepinone from a monosubstituted oxazepinone. After first protecting the ring nitrogen with one of several amide protecting groups known to those skilled in the art, treatment with a strong base followed by an alkyl iodide gives after protecting group removal, a 3,3-disubstituted oxazepinone. Using the same sequence of reactions, a 3-monosubstituted oxazepinone (Ra above is H) can also be synthesized from a 3-unsubstituted oxazepinone. 
Compounds of the present invention that are thioamides can be prepared as illustrated in Scheme 14 by treating the corresponding amides with either Lawesson""s reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide] or phosphorous pentasulfide. 
Compounds of the present invention in which Ra or Rb are vinyl or cyclopropyl can be prepared as illustrated in Scheme 15. 2-Aminoarylketones protected, for example, with an N-p-methoxybenzyl (PMB) group can be treated with an acetylide to give the corresponding acetylenic alcohol. Cyclization can be effected by 2,4-dibromobutyryl chloride and the PMB group can then be removed, for example, by treatment with ceric am monium nitrate. Displacement of the bromide with an arylselenide followed by oxidative elimination by treatment with hydrogen peroxide affords the 5-alkynyl-3-vinylbenzoxazepinone. The vinyl group can be converted to a cyclopropane ring by Pd(II) catalyzed reaction with diazomethane. If the acetylenic alcohol is reduced to the olefin with lithium aluminum hydride (LAH), the same reaction sequence can be used to prepare the trans-5-alkenyl-3-vinylbenzoxazepinone and the corresponding trans-5-alkenyl-3-cyclopropylbenzoxazepinone.
One isomer of a compound of Formula I may display superior activity compared with the other. Thus, all four of the following stereochemistries are considered to be a part of the present invention. 
When required, separation of the racemic material can be achieved by HPLC using a chiral column or by a resolution using a resolving agent such as camphonic chloride as in Steven D. Young, et al, Antimicrobial Agents and Chemotheraphy, 1995, 2602-2605. A chiral compound of Formula I may also be directly synthesized using a chiral catalyst or a chiral ligand, e.g., Andrew S. Thompson, et al, Tet. Lett. 1995, 36, 8937-8940. In addition, separation may be achieved by selective cystallization, optionally in the presence of a chiral acid or base thereby forming a chiral salt. other features of the invention will become apparent in the course of the following descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.